The invention relates to a resetting device for microprocessors. Resetting circuits for microprocessors have been known for a long time. On the one hand, they serve to put the microprocessor in a defined output stage when the voltage supply is applied. On the hand hand, resetting circuits have been already suggested, which cause a resetting of the microprocessor, if the program stored in the microprocessor is not orderly operated. For this purpose signals are generated at an output of the microprocessor. These signals occur once during each running through a program, for example. If these signals fail to occur for a long time a resetting pulse is emitted. However, this process of resetting is not reliable in all cases. For example, a failure of the microprocessor may occur when a jump occurs in the program range of the data range (RAM or ROM). The program order is defined by the data stored in the data range. Thus, endless loops can form to which an output of the microprocessor can respond. Although the microprocessor does not function properly no resetting is provided in the known circuits, since pulses are present at the output of the microprocessor. This can result in that the device operated by the microprocessor does not work. In the worst case damages may occur in the device, namely when consumers are switched on, which by definition are only charged for a short time, so that an erroneous circuit of the microprocessor is permanently charged.